Many industries can benefit from mixing different components into a final packaging, for example by mixing a concentrate with a diluted element to achieve a mixture meeting the specification of the final saleable product.
U.S. Pat. No. 5,992,455 Koller discloses a dual stream filling system having a secondary filling tube, fitted with a valve, positioned partly within a primary filling tube. It is clear that a relatively complicated valve closing mechanism needs to be located inside the secondary filling tube. A problem with this apparatus is that hygiene and operation are relatively complex. Another problem is that the apparatus mixes two components inside a nozzle, specifically the secondary filling tube, thus making it impossible to make accurate mid-flow instant changes to the proportions of fluids dispensed.
U.S. Pat. No. 6,772,806 De Villele discloses an apparatus for filling receptacles with two different components, comprising a single carousel providing an inner and outer orbit for the receptacles. A receptacle is initially transported around one orbit of the carousel and filled or partially filled upon arrival at a first of two filling stations, where a nozzle dispenses a weighed amount of one of two components. After passing through the first filling station the receptacle is displaced into the other orbit. The receptacle is then filled upon arrival at a second filling station, where a nozzle dispenses a weighed amount of the second of the two components. A problem with this system is that, as with the Soehnlen apparatus, machines are not utilized to their full filling capacity. Another problem is that the mechanism for transferring receptacles between inner and outer orbits is complex and suffers from increased chances of receptacle breakages.
In one method shown in U.S. Pat. No. 6,446,680 empty milk containers proceed through two filling carousels arranged in series. The first carousel can deliver skimmed milk to the containers on the carousel and the second carousel can deliver full fat milk. The machines are both large and complex. Further, the machines are not utilized to full capacity when containers designated for whole milk only must remain empty as they pass through the skimmed milk carousel.
WO/2006/091159 discloses a method of filling a toothpaste container with two different colored paste such that a lasting pattern is formed. Concentric inner and outer ducts dispense the paste from the filling nozzle with the outlet from each duct having a valve. Mixing of the different colors is to be avoided.
GB 2429262 discloses a shut-off valve assembly for controlling exhaust gas flow of an internal combustion engine. A main valve and an auxiliary valve are provided.
GB 2308174 discloses a single chemical dispenser with a tapered outlet passage leading to an outlet orifice at the bottom end. A drip piston and a dribble piston are also provided. The outlet orifice cannot be opened without the dribble and drip pistons also allowing flow of the single chemical.